FBLN1 Regulates Embryonic Myoblast Proliferation and Differentiation in Geese: Functional Characterization of a Meat Quality‐Associated Candidate Gene From Prior Multi‐Omics Screening

Meat quality is a vital economic trait in geese and is largely determined by embryonic muscle development. Building on previously reported whole-genome resequencing and breast muscle transcriptome data from Xianghai Flying (XHF) Goose and Zi Goose, two breeds with divergent meat quality, fibulin-1 (FBLN1) was identified as a candidate gene showing both strong selection signals and significant differential expression. FBLN1 was overexpressed and knocked down in primary goose embryonic myoblasts. Because no goose-specific antibody is commercially available, all readouts were obtained at the mRNA level. FBLN1 was found to promote myoblast proliferation and to accelerate the G1/S cell cycle transition, with increased expression of CCND1 and CDK2. Apoptosis was concurrently suppressed, accompanied by downregulation of Bax and upregulation of Bcl-2, whereas transcript levels of Caspase-3 and Caspase-9 remained unaltered. The mRNA levels of the myogenic differentiation markers Myomaker, MYOD1, and MYF5 were correspondingly affected. Bioinformatic analyses predicted FBLN1 to be an extracellular matrix protein that interacts with proteins implicated in muscle elasticity, tenderness, and juiciness. These findings suggest that FBLN1 plays an important role in embryonic myoblast development and represents a valuable candidate gene for improving goose meat quality, thereby offering new perspectives for poultry molecular breeding.